2.2.2.: Classification criteria

2.2.2.1. A flammable gas shall be classified in this class in accordance with Table 2.2.1:


Table 2.2.1

Criteria for flammable gases

Category

Criteria

1

Gases, which at 20 °C and a standard pressure of 101,3 kPa:

(a)  are ignitable when in a mixture of 13 % or less by volume in air; or

(b)  have a flammable range with air of at least 12 percentage points regardless of the lower flammable limit.

2

Gases, other than those of Category 1, which, at 20 °C and a standard pressure of 101,3 kPa, have a flammable range while mixed in air.

Note:

Aerosols shall not be classified as flammable gases; see section 2.3.

2.2.2.2. A flammable gas that is also chemically unstable shall additionally be classified in one of the two categories for chemically unstable gases using the methods described in Part III of the UN RTDG, Manual of Tests and Criteria according to the following table:


Table 2.2.2

Criteria for chemically unstable gases

Category

Criteria

A

Flammable gases which are chemically unstable at 20 °C and a standard pressure of 101,3 kPa

B

Flammable gases which are chemically unstable at a temperature greater than 20 °C and/or a pressure greater than 101,3 kPa